Put a brake on any magical made-for-Disney tales of Kurt Warner, the grocery-clerk-turned-NFL MVP. Hold off on possible made-for-TV screenplays about Michael Lewis, the tiny wide receiver who ended up in pro football because of a radio commercial he heard while delivering beer in a big rig.

We may have a more cinematic working-class hero down in Santa Clara, hustling for a job with the 49ers. Jasen Isom hasn't made it in the NFL yet, because a season on the 49ers' practice squad doesn't count in Hollywood. It barely counts in the NFL, but there is so much potential here. This is a kid who keeps hanging onto the fringes of his sport like an action hero dangling from a window ledge, until his survival becomes a miracle.

If Isom, now taking his third shot at the roster, ever becomes a regular at fullback, the opening scene of that movie is already written.

The camera pans a high school hallway, briefly pausing at pictures of star athletes from the school's past. Slowly, the shot narrows, pulling in toward a sturdy young man with a mop. We get a close-up of his face. He looks a lot like Vin Diesel, which should help with casting. He looks exactly like one of the star athletes whose likenesses hang on the wall.

It's all true. In the fall of 2001, after the 49ers cut him on his first go- round with them, Isom went home to Wheatley Heights, N.Y., on Long Island, and realized that he needed to get a real job. Not a permanent job, mind you. When Isom thought long-term, he was still fixated on pro football. So he signed on to be a janitor in his old school district.

"It was a very humbling experience," Isom said Saturday after the first session of a 49ers minicamp. "People knew who I was, and they heard I was trying out with the 49ers, so when they saw me, they'd say, 'What are you doing here?' . . . I told them, 'I've got to work.' "

Note to studio bosses: The writers will have to juice up the pathos on this.

Isom doesn't give you much to work with. He'll start telling you how hard it was to take that long flight back to New York right after he was cut the first time, or how he felt watching games on TV that year, but he never moves into a nice, dramatic, wallowing phase.

Before you know it, he's got his chin up and his "lucky-to-be here" attitude perfectly in place. He says his parents taught him that. His dad, John, played some semipro football. His mother, Gaye, is a police officer. Apparently, they helped their son accept the reality of hard work and the value of dreams that don't disappear when you wake up.

Actually, Isom's resume makes the NFL seem less like a dream for him, and more like a hallucinogenic fantasy. Stardom at Half Hollow Hills High (how Hollywood-ready is that name?) didn't mean much to Division I colleges.

A reasonable young man would have quit long ago, well before the 49ers jettisoned him into a winter of janitorial work. But who makes movies about reasonable men? And reasonable young men don't get anywhere near the NFL after a) not getting a college scholarship out of high school, b) still not getting a scholarship after a year at prep school to boost his standardized test scores, c) going to the University of Cincinnati and still not getting a scholarship, even after starting a few games, and d) finally earning a scholarship on the third try (Or is it fourth? So hard to keep track.) by transferring to Division I-AA Western Illinois.

When NFL scouts came to his school, mostly to see two other players who ended up being drafted in the second and third rounds, Isom would be an incidental character on the field. The Niners noticed him, though, and called him on draft day -- after the draft was over. They brought him into camp as a rookie free agent.

When they released him that first year, Isom took the janitor's job because it allowed him to prepare for the next training camp. He started on the 3-to- midnight shift, and got up in time to start working out at 9 a.m., continuing for as long as four hours.

"I've always been a hard worker, but after that (the release), I worked even harder," he said.

He had to train in horrible weather and a tiny gym, and he was constantly exhausted. "Very tired," he remembered, his eyes taking on a weariness rare in a 26-year-old.

The film can capture that grind. It may seem too derivative of "Rudy," but some cable network may want to capitalize on the Notre Dame haters who boycotted that movie. The NFL and the 49ers should get behind the idea, because underdog stories are so charming, and, for the Niners, this one surpasses even Jeff Garcia's glorious return from exile in Canada.

Lewis and the beer truck may have a slight edge, because there is something comical about a guy responding to an ad for the Bayou Beast and eventually moving all the way from an indoor football league to the NFL.

But picture this: The camera has left Isom in the school hallway, where teenagers are amazed to see him cleaning up. In the next shot, he is in a 49ers uniform, telling reporters about all of the coaches who passed him over. Finally, someone looks up from a notebook and asks the same question as the kids at Half Hollow Hills: "What are you doing here?"

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